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Biomedical subjects

A Wolfson

Publications and source records attributed to A Wolfson.

At least 19 recordsLinked to original sources

Prognostic factors and survival in patients with spinal cord gliomas after radiation therapy.

The purpose of this study was to determine the impact of various prognostic factors on survival in spinal cord gliomas treated with radiation. Fifty-three patients with spinal cord gliomas irradiated at three major institutions were studied. Fifty-one patients were classified as having ependymoma, astrocytoma, or both. Two patients were classified as having gliomas (otherwise unspecified). Eleven patients had complete resection of their tumor. Biopsy or partial resection was done in the remaining patients. All patients received external beam radiation. Information on these patients was placed in a central database file and analyzed for the effect of several prognostic factors on survival. Overall survival of the entire group was 76.9% and 61.5% at 5 and 10 years, respectively. Pathologic status significantly affected survival (p = 0.03). Patients with ependymomas had a 5-year survival of 93.8% and a 10-year survival of 67.5%. Patients with astrocytoma had a 5-year survival of 64.2% and a 10-year survival of 54%. Univariate analysis showed pathology and the presence of cysts (p = 0.038) to significantly affect survival. Age, sex, location of the primary, extent of surgery radiation dose, and number of involved segments did not affect survival. On multivariate analysis, astrocytic pathology, involvement of more than five segments, male sex, and the absence of cysts (in or adjacent to the tumor) were associated with a significantly inferior survival. This study confirms the importance of pathology and number of segments involved in determining outcome or survival. The presence of cysts adjacent to or within the tumor was found to be associated with an improvement in survival.

Adolescent↗

The importance of postoperative radiation therapy in multimodality management of locally advanced breast cancer: a phase II trial of neoadjuvant MVAC, surgery, and radiation.

PURPOSE: To determine the impact of postoperative radiation on locoregional relapse and overall survival rate in a multimodality protocol for locally advanced breast cancer (LABC). MATERIAL AND METHODS: Of the patients entered in the protocol, 55 were evaluable. Treatment consisted of: neoadjuvant MVAC (methotrexate, vinblastine, adriamycin, and cisplatin) until a maximum response had been achieved; modified radical mastectomy; 6 courses of postoperative adjuvant MVAC chemotherapy, and chest wall irradiation (CWXRT). Multivariate analysis of locoregional response and overall survival was done. RESULTS: Of the total, 42 patients received chest wall radiation; 28 of these also received radiation to regional lymph nodes. Chest wall doses ranged from 45 Gy to 50.4 Gy to the whole chest wall, with 31 patients receiving an additional chest-wall boost. The incidence of locoregional relapse with and without radiation was 7% vs. 31%, respectively (p = 0.026). An overall survival benefit was seen in those receiving radiation, with a mean overall survival of 50 months vs. 20 months, and a 3-year overall survival of 88% vs. 46% with and without radiation, respectively (p = 0.003). Multivariate analysis showed that overall survival was affected by the presence of pathological CR (p = .047), the number of pre-operative chemotherapy cycles (p = .036) and whether or not they received radiation (p = 0.003). Neither the interval between surgery and radiation, technique of radiation, nor radiation modality significantly affected local control. CONCLUSION: The significant improvement in local regional control and overall survival with the addition of radiation suggests that radiation should be an integral part of multimodality management of locally advanced breast cancer.

Adult↗

Hyperfractionated radiation therapy and 5-fluorouracil, cisplatin, and mitomycin-C (+/- granulocyte-colony stimulating factor) in the treatment of patients with locally advanced head and neck carcinoma.

BACKGROUND: The authors had previously reported preliminary results of a treatment regimen of concurrent hyperfractionated radiation therapy and chemotherapy in patients with locally advanced head and neck carcinoma that demonstrated both feasibility and high local control. In an attempt to reduce acute mucosal and hematologic toxicity, granulocyte-colony stimulating factor (G-CSF) was added during the second phase of this study. METHODS: Seventy patients (53 with Stage IV and 17 with Stage III disease) were entered between May 1988 and June 1995 into a Phase I/II trial of concurrent radiation therapy (74.4 gray (Gy) total dose; 1.20 Gy twice daily), 5-fluorouracil (1000 mg/m2/24 hours for 72 hours), and cisplatin (50 mg/m2) for 3 cycles with the addition of mitomycin C (8 mg/m2) in Cycle 2. G-CSF was added after the initial entry of 34 patients. RESULTS: At a median follow-up of 41 months (range, 12-80 months), 44 patients were alive with a projected median overall survival of 54 months. Grade 3/4 mucositis, observed in 65% of patients, was equally prevalent and prolonged in both G-CSF-treated (+) and G-CSF-naive (-) patients. Grade 3/4 leukopenia was present in 45% and 36% of G-CSF- and G-CSF+ patients, respectively. The 3-year locoregional control and cause specific survival rates were 68% and 75%, respectively. CONCLUSIONS: This regimen was feasible and effective but caused severe mucositis. No benefit was derived from the addition of G-CSF. This regimen deserves further modification to reduce acute mucositis toxicity yet maintain the high locoregional control rate.

Adult↗

Mechanisms of inhibition of IL-6-mediated immunoglobulin secretion by dexamethasone and suramin in human lymphoid and myeloma cell lines.

The cytokine IL-6 has been proposed as an autocrine growth factor in multiple myeloma, and is also required for stimulation of immunoglobulin production and secretion in normal plasma cells and myeloma cells. In this study, we showed that secreted IL-6 is detectable by Western blot analysis in a panel of lymphoid and myeloma cell lines. Previous studies in our laboratory have shown that dexamethasone and suramin inhibit cell proliferation and IL-6-mediated immunoglobulin secretion in various lymphoblastoid and myeloma cell lines. In the present study, we present study, we present data to examine mechanisms by which dexamethasone and suramin inhibit IL-6-mediated immunoglobulin secretion in the lymphoid cell line SKW 6.4. Cells treated with rIL-6 or the IC10 concentration of dexamethasone respectively undergo a doubling of intracellular IgM. Moreover, rIL-6 and dexamethasone additively stimulate cells to accumulate intracellular IgM. In contrast, cells treated with the IC10 concentration of suramin undergo no significant alteration of total cellular IgM, and do not respond to IL-6 with an increase in intracellular IgM. Northern blot analysis demonstrates that cells treated with exogenous rIL-6 and/or dexamethasone respectively undergo a coordinate one to three fold increase of kappa and mu chain mRNA expression, while there is a 30-40% decrease of kappa and mu chain mRNA when cells are treated with suramin and suramin plus rIL-6. Western blot analysis shows that levels of intracellular IL-6 modestly increase when cells are treated with exogenous rIL-6, whereas treatment with dexamethasone plus rIL-6 causes a 70% decrease of immunoreactive IL-6 protein in comparison with untreated cells. An rtPCR analysis of IL-6 mRNA expression shows an abolished signal in response to dexamethasone or rIL-6 and/or dexamethasone. Using a flow cytometric assay, it is demonstrated that suramin inhibits IL-6 binding to its receptor. Taken together, these results indicate that SKW 6.4 cells treated with rIL-6 and/or dexamethasone undergo increased expression of IgM mRNA leading to increased intracellular IgM levels. Treatment with suramin or suramin plus rIL-6 does not alter the IL-6 protein level or the mRNA levels for IL-6 and IL-6 receptor. Suramin treatment causes a moderate decrease in IgM mRNA, and this is associated with a decreased intracellular level of IgM in SKW 6.4 cells. Overall these findings support the concept that IL-6 is an autocrine factor for immunoglobulin production and secretion in myeloma cells. Suramin interferes with IL-6 binding to its receptor and/or decreases IL-6 receptor expression. Dexamethasone has neither of these effects on IL-6 receptor expression or IL-6 binding to its receptor, and we postulate that it acts through a block in secretion or in degradation of intracellular immunoglobulin by decreasing IL-6 mRNA expression and IL-6 protein content. These studies suggest that the combination of suramin and dexamethasone not only synergistically growth inhibit myeloma cells but also act in concert to inhibit immunoglobulin secretion and represent a therapeutic approach worthy of further investigation.

Animals↗

Retrospective epidemiologic analysis of patients diagnosed with intracranial meningioma from 1977 to 1990 at the Jackson Memorial Hospital, Sylvester Comprehensive Cancer Center: the Jackson Memorial Hospital Tumor Registry experience.

A descriptive analysis was performed of the Tumor Registry data for intracranial meningioma by the Jackson Memorial Hospital, University of Miami School of Medicine Tumor Registry. A total of 108 cases of intracranial meningioma was collected and reviewed. Overall survival for 2, 5, and 10 years was 82, 72, and 60%, respectively. There was no difference in survival for males and females at 5 years, nor any difference in survival for race or ethnicity. There was a trend for improved survival for the young age group (18-55 years).

Adult↗

Dexamethasone and suramin inhibit cell proliferation and interleukin-6-mediated immunoglobulin secretion in human lymphoid and multiple myeloma cell lines.

Uncontrolled growth of neoplastic cells and unregulated production of immunoglobulin are major components of the morbidity and mortality of multiple myeloma. Suramin, a polysulfonated napthylurea, has antitumor activity in a number of malignancies, but also significant dose-related toxicity. Suramin has been reported to have major antiproliferative effects in a variety of lymphoid cell lines. Glucocorticoids have long been recognized to have activity in lymphoid malignancies and multiple myeloma while IL-6 has been reported to be an autocrine growth factor for multiple myeloma. This study examines growth inhibition and inhibition of IL-6-mediated secretion of immunoglobulin in human lymphoid and myeloma cell lines by dexamethasone and suramin. Dexamethasone and suramin show synergistic inhibition of cell proliferation at their IC10 concentrations. IL-6-mediated immunoglobulin secretion is also inhibited by both dexamethasone and suramin in an additive fashion. Both dexamethasone and suramin induce apoptosis of lymphoid cell lines, and suramin inhibits the binding of IL-6 to its receptor in a multiple myeloma cell line. These findings suggest that the synergistic growth inhibitory activities of dexamethasone and suramin may be related to induction of apoptosis by both agents and inhibition of IL-6-mediated autocrine growth stimulation and immunoglobulin production. These results indicate that the combination of low-dose suramin (in concentrations not associated with significant clinical toxicity) and dexamethasone merit further study in the treatment of myeloma or lymphoid malignancies.

Antigens, CD↗

Effects of parent training on infant sleeping patterns, parents' stress, and perceived parental competence.

First-time parent couples from childbirth classes were randomly assigned to a four-session training group (n = 29) or a control group (n = 31). Members of the training group were taught behavioral strategies to promote healthy, self-sufficient sleep patterns in their infants, whereas the control group received the same amount of personal contact without the behavioral training. Six sleep variables were derived from a daily infant sleep diary completed by parents at two time points. Results show that at age 6-9 weeks, infants in the training group displayed significantly better sleeping patterns than did control infants. Training group parents awakened and responded less often to infant signaling and reported greater parental competence. By contrast, control group parents indicated increased stress over time.

Adaptation, Psychological↗

Comparative study of subunits of phenylalanyl-tRNA synthetase from Escherichia coli and Thermus thermophilus.

FPLC separation of alpha- and beta-subunits of phenylalanyl-tRNA synthetases from E. coli MRE-600 and Thermus thermophilus HB8 has been carried out in the presence of urea. Native alpha-subunits of both enzymes were primarily alpha 2-dimers and tended to aggregate. Most E. coli enzyme beta-subunits were monomeric and only a small fraction was represented by beta 2-dimers. All thermophilic beta-subunits were beta 2-dimers. It was shown that monomers and all forms of homologous subunits had no catalytic activity in tRNA(Phe) aminoacylation. For the enzymes and their subunits, titration curves were obtained and isoelectric points were determined. The comparison of the relative surface charges indicated similarity of the surfaces of entire enzymes and the corresponding beta-subunits. Alpha-subunits displayed a distinctly different pH dependence of the surface charge. A spatial model of the oligomeric structure and a putative mechanism for its formation are discussed.

Chromatography↗

External beam radiotherapy for primary spinal cord tumors.

Of 34 evaluated patients with primary spinal cord tumors, 32 were irradiated at our institutions between 1969 and 1983. The results are reported of 32 patients, 16 with ependymoma and 16 with astrocytoma, who were treated with postoperative external beam radiotherapy following biopsy or subtotal resection. Twenty-nine patients received 45-55 Gy megavoltage beam irradiation in five to six weeks, and the remaining three patients received less than 40 Gy. The minimum follow-up was five years. Five- and ten-year actuarial survival rates for the entire group of patients were 73% (22/30) and 50% (8/16), respectively, including three patients who were salvaged by surgery after radiotherapy failures. Corresponding five- and ten-year relapse-free survival rates were 60% (18/30) and 32% (6/19), respectively. Of the 29 patients who received more than 45 Gy, relapse-free survival at five years was 63% (17/27). Treatment failed in 13 patients, and all of those failures were within the irradiated portals. Patients with ependymomas have significantly better relapse free survival than those with astrocytomas, 80% vs. 40% (p less than 0.05). There was a significant difference in survival between patients with tumors involving the cervical spine and those with tumors in the other locations, 45% vs. 89% (p less than 0.05). There was no significant difference in survival between patients with cauda equina tumors and those with tumors of the spinal cord, 100% vs. 68% (p less than 0.05). No radiotherapy-related neurological deficit was noted with a maximum 20 year follow-up. This study confirms that external beam radiotherapy is a safe and effective treatment modality for primary spinal cord tumors.

Adult↗

Temperature dependence of the dissociation rate constants for the nonactivated (molybdate-stabilized) and activated progesterone receptor-hormone complexes from the chick oviduct.

Both the nonactivated and activated forms of the chick oviduct cytosol progesterone receptor-hormone complexes displayed first-order dissociation kinetics at temperatures between 0 and 25 degrees C. The rate constant was always 2-3-times greater for the nonactivated than for the activated complex. The thermodynamic parameters calculated from the Eyring plot for the nonactivated and activated forms, respectively, were: delta H+ = 28.6 +/- 0.2 and 29.9 +/- 1.5 kcal/mol; -T delta S+ = 7.4 +/- 0.6 and 7.7 +/- 1.6 kcal/mol; and delta G+ = 21.3 +/- 0.5 and 22.1 +/- 0.1 kcal/mol. These values suggest that activation results in an increase in enthalpy of the ligand-receptor interaction, thus stabilizing the complex. The dissociation rate constants for the native complex obtained by two different experimental approaches, namely, isotope dilution ('chase') and dissociation against charcoal, indicated the absence of cooperativity in the receptor-ligand binding.

Animals↗

Activation of the chick oviduct progesterone receptor by heparin in the presence or absence of hormone.

Activation (transformation) of the chick oviduct progesterone receptor was found to be induced at 0 degrees C by heparin free in solution as well as by chromatography on a column of heparin linked to acrylamide/agarose. The transformed molecule displayed properties of the activated form of [3H]progesterone-receptor complex obtained by heat treatment or by high ionic strength: smaller size (s20,w = 3.9 S, Stokes radius = 5.2 nm), lower rate of dissociation (t 1/2 approx. 50 h at 0 degrees C compared with approx. 20 h for the 'native' form) and increased binding to phosphocellulose. In all cases, molybdate was an effective inhibitor of transformation and stabilized a large 'native' form (s20,w = 7.9 S, Stokes radius = 7.6 nm). Transformation by neither KCl nor heparin depended on the presence of ligand bound to the receptor, and the properties of the receptor molecule produced by treatment of ligand-free receptor with high ionic strength or with heparin were identical with those of the activated progesterone-receptor complex, demonstrating that receptor activation can be obtained experimentally in the absence of hormone. Our data are compatible with a model in which activation implies separation of the 4 S units, which compose the approx. 8 S 'native' form.

Animals↗

Progesterone receptor from chick oviduct: purification of molybdate-stabilized form and preliminary characterization.

A molydate-stabilized, 'non-activated' form of the progesterone receptor from the cytosol of oestrogen-stimulated chick oviduct has been purified to homogeneity by a three-step procedure. The first step, affinity chromatography using a N-(12-amino-dodecyl)-3-oxo-4-androsten-17 beta-carboxamide-substituted Sepharose gel, purified the receptor 1500-2700-fold with approximately equal to 50% recovery. In the second step, ion-exchange chromatography through a DEAE-cellulose column, progesterone receptor was eluted as a single peak at 0.1 M KCl. Purification after this step was greater than 6700-fold. The third step was filtration through Ultrogel AcA 34, resulting in overall purification approximately equal to 7400-fold with overall recovery approximately equal to 25% of pure receptor on the basis of 1 binding site/molecule of Mr 85000. The purified molybdate-stabilized receptor had a sedimentation coefficient approximately equal to 7.9S +/- 0.1 (n = 4) in 0.15 M or 0.4 M KCl containing sucrose 5-20% gradient and approximately equal to 8.9S +/- 0.2 (n = 6) in 0.15 M KCl containing glycerol 10-35% gradient, and its Stokes radius was 7.05 +/- 0.10 nm (n = 3) (calculated Mr between 240000 and 280000). Binding specificity of the purified receptor was the same as that found in crude cytosol. SDS-PAGE revealed a single band migrating as a polypeptide of Mr approximately equal to 85000 +/- 2300 (n = 9). PAGE under non-denaturing conditions at total acrylamide concentrations 5%, 7% and 9% showed a single [3H]ORG 2058-protein band (ORG 2058 is a high-affinity analogue more suitable than progesterone for electrophoretic studies). The data suggest that the high molecular weight molybdate-stabilized progesterone receptor purified from oestrogen-primed chick oviduct is composed of only approximately equal to 85000-Mr polypeptide chains.

Animals↗